The present invention relates to an exposure method and its pattern preparation technology, and particularly relates to an effective technology to be applied to an exposure method and pattern data preparation system used therefor, pattern data preparation method and a mask as well as an exposure apparatus, where in exposure of integrated circuit patterns of a semiconductor integrated circuit device, periodic and repeated patterns can be exposed at high speed and high precision by irradiation of a focused beam of electron rays or the like.
For example, in a manufacturing process of a semiconductor integrated circuit device, various types of fine processing technology using focused beams have been put to practical use, such that an integrated circuit pattern is drawn to a photo mask (reticle) or a semiconductor wafer using an electron beam or a laser beam, and a defective portion of an integrated circuit pattern is corrected using a focused ion beam.
Among the focused beam processing technologies, the use of electron beams to irradiate a wafer coated with an electron ray sensitive resist thereon and an integrated circuit pattern exposed directly onto the wafer have become widely used in recent years, in comparison with conventional light exposure technology having an integrated circuit pattern formed on a photo mask which is transferred to a wafer, because a fine integrated circuit pattern can be formed on the former.
In the focused beam processing technology, a focused beam is computer-controlled based on design data of an integrated circuit, and the beam and a sample are positioned exactly, thereby fine processing with high precision is realized.
Also in the method using focused beams, in general, since a pattern is formed by a quite finely focused beam there is a problem. In order to improve the throughput significantly, a method is disclosed, for example, in JPA No. 260322/1987, where a graphic unit having repeated graphics is formed with an aperture of graphic form (hereinafter referred to as "mask") formed at a prescribed position in a column through which an electron beam for example is transmitted, thereby the electron beam is shaped in the mask is irradiated repeatedly.
That is, a beam of a relatively large diameter is selectively transmitted through an aperture of a mask in a small domain on the mask and the mask is beam-shaped, and this is transferred onto the resist by irradiation. The optical system of the electron beam apparatus in the above-mentioned system is disclosed in U.S. Pat. No. 4,213,053.
An explanation of this system is disclosed in a reference such as "Semiconductor World, July 1990" pp. 170-175, published on Jun. 20, 1989 by Press Journal Co., Ltd.
Further, an FIB (Focused Ion Beam) apparatus is used as an apparatus having a narrowed ion beam irradiated on a semiconductor wafer to perform a process treatment of the semiconductor wafer. Regarding the FIB apparatus, a control file and control method are described in SPIE vol. 632 Electron-Beam, X-Ray, & Ion-Beam Technique For Submicrometer Lithographies V(1986) pp. 85-92 for example.